1. Field of the Invention
This invention relates generally to connectors for various tubular medical devices, and, more specifically, to a popoid type connector that is capable of being bent relative to a longitudinal axis thereof and is configured to maintain the bent position.
2. Background of the Invention
Popoids are typically formed into plastic tubing to allow bending of the plastic tubing without causing the plastic tubing to kink. A popoid is generally comprised of a plurality of saw tooth sections that are circumferentially formed into the wall of the tubing. When collapsed, each saw tooth section abuts against and fits slightly within the adjacent saw tooth section effectively shortening the length of tubing from which the popoid is formed. In an expanded position, the popoid is capable of bending in any direction (i.e., 360 degrees) relative to the longitudinal axis of the tubing in which the popoid is formed and will generally hold its bent position when released.
Popoid devices are used in many applications both inside and outside the medical industry. For example, plastic drinking straws have been available for many years that include a popoid section proximate the drinking end thereof to allow the straw to bend along the popoid section and thus maintain its bent shape when released. In the medical industry, popoid devices have been developed for use where typically more rigid tubing devices require bending or flexing without causing the tubing to become kinked. For example, endotracheal tubes are typically formed from a sufficiently rigid plastic material to maintain an open airway through the trachea of a patient. The proximal end of such an endotracheal tube is often connected to other sections of tubing outside the patients body. In order to place less stress on the endotracheal tube as it exits the patient and thus increase patient comfort, connectors have been developed that utilize a popoid section to join the endotracheal tube with another external section of tubing. These popoid connectors allow an abrupt bend to be made in the tubing connected to the endotracheal tube proximate the end of the endotracheal tube exiting the patent that places the least amount of force on the proximal end of the endotracheal tube. Such popoid connectors are also advantageous for use in conjunction with other medical devices such as those used for intubation applications as well as in various breathing circuits for aspiration and/or ventilation.
Tubular popoid connectors are typically formed from extruded sections of plastic tubing. Often, shortly after extrusion, the sections of plastic tubing are placed within a mold. Because the sections of plastic tubing are placed within the mold shortly after extrusion, the sections of tubing are still in a pliable state and have thus not yet complete solidified. As such, the sections of tubing are amenable to being molded. The molds include recesses formed therein that are configured to define the popoid connector Such molds are generally formed from two matching half molds, each of which define a plurality of semicircular recesses as well as the other desired features of the popoid connector. When mated, the two matching half molds form the complete desired shape of the popoid connector.
As each section of tubing is placed within the mold, the tubing is forced into the recesses of the mold to cause the tubing to form to the inside of the mold. Such force is usually applied by using suction on the external surfaces of the tubing to draw the tubing into the recesses of the mold, or by pressurizing the inside of the section of tubing to cause the tubing to expand into the internal recesses of the mold. Because the section of tubing is often comprised of a relatively thin walled, plastic material, the section of tubing rapidly cools to rigidly maintain the shape of the mold upon its release from the mold.
FIGS. 1 and 2 illustrate a popoid connector, generally indicated at 10, known in the art. The popoid connector 10 is comprised of a generally elongate tubular member having a distal end 12 and a proximal end 14. A first connection end 16 is provided at the distal end 12 and includes various features 18, 20, 22 and 24 for connecting to another device, such as an endotracheal tube (not shown). Likewise, the proximal end 14 has a similarly configured second connection end 26 that includes features 28, 30, 32, and 34 for attachment to another medical device.
Interposed between the first and second connecting ends 16 and 26, respectively, is a popoid section, generally indicated at 38. The popoid section 38 is comprised of a plurality of corrugations 40-47 that have a configuration which allows the popoid section 38 to bend and retain its bent orientation when released. Each corrugation 40-47 is comprised of a pair of oppositely facing frustoconical sections, such as the frustoconical sections 48 and 50 of corrugation 41. While the largest and smallest diameters of the frustoconical sections 48 and 50 are the same, the longitudinal length of each frustoconical section 48 and 50 is different. In this example, the frustoconical portions 48 nearest the distal end 12 of each corrugation 40-47 have a greater longitudinal length than the longitudinal length of the frustoconical sections 50 nearer the proximal end 14. When the distal end 12 is forced toward the proximal end 14 along the longitudinal axis of the connector 10, the frustoconical portions 48 substantially maintain their shape, while the frustoconical portions 50 become inverted to fit within the associated frustoconical portions 48. Thus, the popoid section 38 will collapse upon itself to shorten the length of the connector 10. A similar condition occurs when the popoid section 38 is bent in a direction relative to the longitudinal axis of the connector 10. As the popoid section 38 is bent, the sides of the frustoconical portions 48 and 50 on the side of the popoid section that are in the direction of the bend will fold upon themselves to shorten the length of the popoid along that side. Conversely, the frustoconical portions 48 and 50 that are on the opposite side to the direction of the bend maintain their pre-bent arrangement such that the length of the popoid section 38 along this side of the popoid section 38 maintains its length.
In order for the popoid to function properly, the frustoconical sections 50 must be able to flex relative to the frustoconical sections 48 to be able to invert when the popoid section 38 is bent or collapsed and maintain their position when released. Thus, the frustoconical sections 48 are configured with an angle between their outer surface and the longitudinal axis of the connector 10 that is less than the angle between the longitudinal axis and the outer surface of the frustoconical sections 50. As such, the frustoconical sections 48 are more difficult to collapse than the frustoconical sections 50.
One problem with such prior art popoids, however, has been their generally flexible nature even when placed in a bent position. Because each portion of the popoid is formed from the same length and strength of plastic tubing, even the frustoconical portions that are less likely to flex when the popoid is bent, as previously discussed, are somewhat easy to flex themselves and thus do not create as rigid a structure as may otherwise be desirable. Thus, it would be advantageous to provide a popoid connector that is substantially more rigid than popoid connectors known in the art. It would also be advantageous to provide such a popoid connector without increasing the wall thickness of the tubing from which the popoid connector is formed. It would be a further advantage to provide a popoid connector that is substantially more rigid than popoid connectors known in the art that can be manufactured in a manner that is simple and relatively inexpensive compared to manufacturing techniques utilized for manufacturing popoid connectors known in the art.
Accordingly, a flexible connector, commonly referred to as a popoid connector, for interconnecting a pair of medical devices is provided in accordance with the principles of the present invention. The popoid connector is comprised of an elongate section of tubing having distal and proximal ends for connection to other medical devices. The tubing, while being generally cylindrical in overall shape, is provided with a corrugated portion comprised of a first set of frustoconical members and a second set of frustoconical members. The first set of frustoconical members alternate with and face in an opposite direction to the second set of frustoconical members to form corrugations in the tubing.
In a preferred embodiment, each corrugation is provided with at least one reinforcing rib circumscribing the corrugation. The reinforcing rib is preferably formed into the first set of frustoconical members. The first set of frustoconical members are preferably the set that substantially maintain their relative orientation with the popoid connector is bent or longitudinally collapsed.
Each of the frustoconical members has a slope defined by its outer surface. Preferably, the slope, relative to a longitudinal axis of the tubing, defined by the outer surface of the second set of frustoconical members is greater than the slope defined by the outer surface of the first set of frustoconical members. This variation of slope determines which portions of the popoid collapse when the popoid is bent or longitudinally compressed. That is, the portions that have the least amount of slope have greater structural strength against longitudinal forces applied to the popoid connector and will thus resist collapsing.
In yet another preferred embodiment, the frustoconical members of the popoid connector define an outer diameter and an inner diameter wherein the outer diameter is approximately equal to a diameter of the tubing.
In still another preferred embodiment, the inner diameter of the frustoconical members is substantially equal to a diameter the tubing.
In still another preferred embodiment, the reinforcing rib comprises a ring integral with and circumscribing an outer surface of an associated frustoconical member.
In yet another preferred embodiment, each pair of said frustoconical members defines an apex. The reinforcing rib is preferably positioned proximate to the apex.
In another preferred embodiment, the reinforcing rib comprises a first reinforcing rib positioned proximate to the apex of the frustoconical members and a second reinforcing rib is positioned proximate to the first reinforcing rib.
In yet another preferred embodiment, a third reinforcing rib is positioned proximate to the second reinforcing rib.
In still another preferred embodiment, the reinforcing rib is integrally formed with the apex of the frustoconical members.
In accordance with another aspect of the invention, the reinforcing rib has a width that is substantially greater than its height.
In accordance with yet another aspect of the invention, the reinforcing rib has a width that is substantially equal to its height.
In still another preferred embodiment, the reinforcing rib is formed on the inside of the first set of frustoconical members.
In yet another preferred embodiment, the reinforcing rib is formed into the second set of frustoconical members.
In another preferred embodiment, the reinforcing rib is positioned proximate to a base of the frustoconical member.
In another preferred embodiment, the popoid connector includes a plurality of saucer shaped members integral with and forming a corrugated section along a length of an tubular member. Each of the saucer shaped members define at least one circumscribing rib integrally formed therewith and protruding therefrom.
The circumscribing ribs may be formed on any outer or inner surface of the saucer shaped members depending upon the desired structural rigidity of the resulting popoid connector. Preferably, however, a pair of circumscribing ribs are provided on the exterior surface of each of the saucer sections on the side of the saucer section that resists longitudinal collapsing when the popoid connector is bent or longitudinally collapsed.
Other objects and advantages of the present invention will become apparent upon reading the following detailed description and appended claims, and upon reference to the accompanying drawings.